Hart I C, Bines J A, Morant S V
J Dairy Sci. 1979 Feb;62(2):270-7. doi: 10.3168/jds.S0022-0302(79)83235-X.
Measures of hormones and metabolites in blood plasma of high and low yielding cattle matched for diet and stage of lactation were investigated for relationships between milk yield, body weight, and concentrations of hormones (prolactin, growth hormone, insulin, and thyroxine) and metabolites (glucose, nonesterified fatty acids, beta-hydroxybutyric acid, and L-lactic acid) for stages of lactation. A first approach correlated total milk yields of 15 cows with average constituents during the four 24-h blood samplings through the first 27 wk of lactation. The second examined associations of changes with sampling periods in milk yield or body weight with changes in hormones and metabolites. Total milk yield of the high yielding group was correlated positively with ratios of growth hormone/thyroxine and glucose/thyroxine and correlated negatively with thyroxine. Changes in growth hormone and its ratio to insulin, and changes in yield were correlated positively for groups combined. Changes in thyroxine were correlated negatively with changes in yield. Changes in liveweight gain were related positively to insulin and lactic acid and negatively with changes in growth hormone. Changes in growth hormone were related positively to changes in nonesterified fatty acids.
对饮食和泌乳阶段相匹配的高产和低产奶牛血浆中的激素和代谢物进行了测量，以研究泌乳阶段牛奶产量、体重与激素（催乳素、生长激素、胰岛素和甲状腺素）和代谢物（葡萄糖、非酯化脂肪酸、β-羟基丁酸和L-乳酸）浓度之间的关系。第一种方法是将15头奶牛在泌乳前27周的四个24小时血样采集期间的总产奶量与平均成分进行关联。第二种方法是研究产奶量或体重随采样期的变化与激素和代谢物变化之间的关联。高产组的总产奶量与生长激素/甲状腺素和葡萄糖/甲状腺素的比值呈正相关，与甲状腺素呈负相关。合并组中生长激素及其与胰岛素的比值变化与产奶量变化呈正相关。甲状腺素变化与产奶量变化呈负相关。体重增加的变化与胰岛素和乳酸呈正相关，与生长激素的变化呈负相关。生长激素的变化与非酯化脂肪酸的变化呈正相关。
